There is often a need to measure the radius of an object, such as a cylinder or a sphere.
Upon information and belief, the conventional way to measure such radii is to measure the diameter of the object with micrometer calipers, and thereafter halve such measured diameter.
Also, upon information and belief, there is a further need to measure the radius of an outside rounded corner, and the radius of a segment of a surface of revolution. There is not believed to be any instrument capable of reading directly such radii.
The most pertinent prior art references known to applicant are U.S. Pat. No. 1,401,119 (Aldeborgh) and U.S. Pat. No. 2,658,911 (Giambiasi). Aldeborgh appears to disclose a diameter gauge having a frame provided with a V-shaped recess and a deviation indicator associated therewith. Hence, Aldeborgh's device is used to indicate deviation from a desired value. Giambiasi discloses a gauge for measuring the taper of a conical object, or the diameter of a cylindrical or spherical object. This reference discloses apparatus having a substantially Y-shaped frame associated with an arm-type deviation indicator. However, there does not appear to be any prospective teaching in Giambiasi that the angle of divergence between the frame legs should be critically related to the scale of a selected micrometer head.